소개
The Defense-in-Depth Validation skill provides a structured framework for making software bugs structurally impossible by enforcing validation across four critical layers: Entry Point, Business Logic, Environment Guards, and Debug Instrumentation. Rather than relying on a single check that might be bypassed by refactoring or mocks, this skill guides Claude to implement redundant but distinct validation checks that protect destructive operations and ensure system reliability. It is particularly useful when dealing with complex data flows, system boundaries, and persistent bugs that are difficult to reproduce or trace.